The invention pertains to a reciprocating wiper system for motor vehicles.
A reciprocating wiper system includes a piston linearly displaceable and guided in a self adjusting bearing of a housing and includes a slide held on the piston. The bearing must be precise and long-lived. Furthermore it is necessary to guide the piston in such a way that it cannot be twisted about its longitudinal axis. In a reciprocating wiper system in which a wiper arm is fastened on the piston, forces act upon the piston which tend to twist it about its longitudinal direction as wiper arm moves a wiper blade across a window pane of a motor vehicle. If the piston is moved to and fro via a crank mechanism it is also affected by torsional forces.
It is possible to support the piston in two bearings spaced apart from each other. For this purpose a slide is mounted onto the end of the piston and the slide extends at least substantially perpendicular to the piston and is longitudinally guided on both sides of the piston by two guide elements fixed to the housing.
While the two bearings determine the longitudinal direction of the piston the latter is protected against twisting by the slide
Another possibility is to directly support the piston in only one bearing and to design the slide and the guide elements in such a way and to arrange them relative to one another that the longitudinal direction of the piston is defined by the three bearings and the piston is protected against twisting at the same time.